These guidelines apply to the foam concentrates for fixed
high-expansion foam fire-extinguishing systems referred to in SOLAS regulation
For the purpose of these Guidelines the following definitions
- Foam (fire fighting): an aggregate of air filled bubbles
formed from an aqueous solution of a suitable foam concentrate.
solution: a solution of foam concentrate and water.
concentrate: the liquid which , when mixed with water in the appropriate
concentration, gives a foam solution.
- Expansion ratio: the ratio of
the volume of foam to the volume of foam solution from which it was made.
- Spreading coefficient: a measurement of the ability of one liquid
to spontaneously spread across another.
- 25% (50%) drainage time: the
time for 25% (50%) of the liquid content of a foam to drain out.
application: application of foam to the surface of a liquid fuel via a
backboard, tank wall or other surface.
- Sediment: insoluble particles
in the foam concentrate.
2 Sampling procedure
The sampling method should ensure representative samples which
should be stored in filled containers.
The sample size
- 30 litres for type tests (see Section 3)
- 2 litres for
periodical controls (see Section 4).
3 Tests for type approval of foam concentrates
For foam concentrate type approval, the tests under paragraphs 3.1 -
3.10 should be performed. They should be carried out at laboratories acceptable to the
3.01 Freezing and thawing
Before and after temperature conditioning in
accordance with 3.1.2, the foam concentrate should show no visual sign of
stratification, non-homogeneity or sedimentation. 3.1.2 Freezing and thawing test
- freezing chamber, capable of achieving
temperatures required as stated in (b.1);
- polyethylene tube,
approximately 10 mm diameter, 400 mm long and sealed and weighted at one end,
with suitable spacers attached. Figure 1 shows a typical form;
- 500 mL
cylinder approximately 400 mm high and 65 mm diameter.
(b.1) Set the temperature of the freezing
chamber to a temperature which is 10 °C below the freezing point of the sample
measured in accordance with BS 5117: Section 1.3 (excluding 5.2 in the standard). To
prevent the glass measuring cylinder from breaking, due to expansion of the foam
concentrate on freezing, insert the tube into the measuring cylinder, sealed end
downward, weighted if necessary to avoid flotation, the spacers ensuring it remains
approximately on the central axis of the cylinder.
Place the sample in the cylinder in the chest, cool and maintain at
the required temperature for 24 h. At the end of this period thaw the sample for not
less than 24 h and not more than 96 h in an ambient temperature of 20-25 °C.
(b.2) Repeat (b.1) three times to give four cycles of
freezing and thawing.
(b.3) Examine the sample for
stratification and non-homogeneity.
(b.4) Condition the
sample for 7 days at 60 °C followed by one day at room temperature.
3.02 Heat stability
An unopened 20 litre container (or other standard shipping
container) as supplied by the manufacturer from a production batch should be maintained
for 7 days- at 60°C, followed by one day at room temperature. Following this
conditioning, the foam liquid after agitating/stirring will be subjected to the fire
test as per 3.8, and comply with the requirements given in these guidelines.
Any sediment in the concentrate prepared in
accordance with Section 2 should be dispersible through a 180 μm sieve, and the
percentage volume of sediment should not be more than 0,25% when tested in accordance
with 3.3.2. 3.3.2
The test should be carried
out as follows:
- graduated centrifuge
- centrifuge operating at 6000 +/- 100 §¾;
- 180 micro m sieve complying with ISO 3310-1;
- plastic wash
NOTE: A centrifuge and tubes
complying with ISO 3734 are suitable.
Centrifuge each sample for 10 min. Determine the
volume of the sediment and determine the percentage of this volume with respect to
the centrifuged sample volume.
Wash the contents
of the centrifuge tube onto the sieve and check that the sediment can or cannot be
dispersed through the sieve by the jet from the plastic wash bottle.
NOTE: It is possible that the test method is
not suitable for some non-Newtonian foam concentrates. In this case an alternative
method, to the satisfaction of the Administration, should be used so that
compliance with this requirement can be verified.
3.04 Kinematic viscosity
3.4.1 - The test should be carried out according to ASTM D
445-86 or ISO 3104. Kinematic viscosity should not exceed 200 mm2/s.
3.4.2 - The method for determining viscosity of
non-Newtonian foam concentrates should be to the satisfaction of the
3.05 Ph value
The pH of the foam concentrate prepared in accordance with Section
2 should be not less than 6,0 and not more than 9,5 at 20 +/- 2) °C.
3.06 Expansion ratio
he test should be carried out according to paragraph
3.6.2, with sea water at about 20 °C. Simulated sea water with the characteristics
stated under 3.6.3 may be used. The expansion ratio obtained with the foam generators
used on board should be consistent with the expansion ratio obtained with the foam
generators during the fire test. 3.6.2
Determination of the expansion ratio
plastic collecting vessel of volume V, approximately 500 L and accurately known to
+/- 5 L;
- high expansion foam-making equipment which when tested
with water has a flow rate of 6.1 +/- 0.1 L/min at a nozzle pressure of (5.0 +/-
An example for a suitable apparatus is given in document
(b.1) Wet the vessel
internally and weigh it ( W1 ). Set up the foam equipment and
adjust the nozzle pressure to give a flow rate of 6.1 L/min. With the discharge
facility closed, collect foam in the vessel. As soon as the vessel is full, stop
collecting foam and strike the foam surface level with the rim. Weigh the vessel (
W2 ). During the filling operation, keep this discharge
facility in the bottom of the vessel closed until the total weight of the foam is
(b.2) Calculate the expansion
E from the equation:
E = V /
(W2 - W1)
in which it is
assumed that the density of the foam solution is 1.0 kg/L and where:
V is the vessel volume, in ml;
the mass of the empty vessel, in grammes;
W2 is the
mass of the full vessel, in grammes.
Assume that the density of
the foam solution is 1.0 kg/L.
the drainage facility and measure the 50% drainage time (see paragraph 3.7.1
Determine the drainage either by having the vessel
on a scale and recording the weight loss, or by collecting the drained foam solution
in a measuring cylinder.
Care should be taken to ensure that there are no
voids in the foam collected in the vessel. 3.6.3
Simulated sea water may be made up by dissolving
25.0 g Sodium
11.0 g Magnesium chloride (MgCl26H2O)
1.6 g Calcium chloride (CaCl22H2O)
4.0 g Sodium sulphate (Na2S04) in
each litre of potable water.
3.07 Drainage time
3.7.1 The drainage time should be determined, after having
determined the expansion ratio, according to paragraph 3.6.2 (b.3).
3.7.2 The test should be carried out with sea water at
about 20°C. Simulated sea water with the characteristics stated in 3.6.3 may be used.
3.7.3 Drainage time obtained with the foam
generators used on board should be consistent with the drainage time obtained with the
foam generators during the fire test.
3.08 Fire tests
Fire tests should be carried out according to the following
paragraphs 3.8.1 to 3.8.7. NOTE: The fire tests
of section 3.8 are more expensive and time consuming than the other tests of these
guidelines. It is recommended that fire tests should be carried out at the end of the
test programme, so as to avoid expense of unnecessary testing of foam concentrates
which do not comply in other respects. 3.8.1
- Air temperature : (15 +/- 5) °C
- Maximum wind speed : 3 m/s in
proximity of the fire tray
During the fire test, record
- indoor or outdoor test
- air temperature
- fuel temperature
- water temperature
- foam solation
- wind speed
- extinction time.
- Prepare a foam solution,
following the recommendations from the supplier for concentration, maximum premix
time, compatibility with the test equipment, avoiding contamination by other types
of foam, etc.
- The test should be carried out with sea water at about 20°C.
Simulated sea water with the characteristics stated in 3.6.3 may be used.
- Fire tray:
Circular fire tray of steel with dimensions as follows:
at rim: : (1,480 +/- 15) mm
depth : (150 +/- 10) mm
nominal thickness of steel wall : 2.5 mm
NOTE: The tray has an area of approximately 1.73
- Foam-making equipment:
In accordance with subparagraph
- Fire screens:
Fire screens of nominal 5 mm
square metal mesh to form the nominal arrangement mentioned in subparagraph 3.8.6.
Use an aliphatic hydrocarbon
mixture with physical properties according to the following specification
NOTE: Typical fuels meeting this specification are n-heptane and certain solvent
fractions sometimes referred to as commercial heptane.
- distillation range : 84 °C - 105 °C
- maximum difference
between initial and final boiling points : 10 °C
- maximum aromatic content :
- density at 15 °C: (707.5 +/- 2.5) kg/m2
- temperature : about 20 °C
The Administration may require additional fire tests
using an additional test fuel. 3.8.6
- Place the tray directly on the ground and ensure that it is
level. Add approximately 30 litres of sea water, or simulated sea water with the
characteristics stated in 3.6.3, and (55 +/- 5) litres of fuel, to give a nominal
freeboard of 100 mm.
- Place the net screens around the fire tray as shown in
figure 2. Within 5 min ignite the fuel and allow it to burn for a period of not less
than 45 s. Commence foam generation with the foam generator some distance from the
fire. (60 +/- 5) s after full involvement move the foam generator to the opening
between the net screen and apply foam to the fire. Apply foam for a period of (120
+/- 2) s. Record the extinction time as the period from start of foam application to
extinction time: not
more than 120 s
The storage container shall be compatible with its foam
concentrate, throughout the service life of the foam, such that the chemical and
physical properties of the foam shall not deteriorate below the initial values accepted
by the Administration.
3.10 Volumic mass
According to ASTM D 1298-85.
4 Periodical controls of foam concentrates stored on board
The attention of the Administration is drawn to the fact that
particular installation conditions (excessive ambient temperature, incomplete filling of
the tank etc.) may lead to an abnormal aging of the concentrates.
the periodical control of foam concentrate the tests under paragraphs 4.1 - 4.5 should be
performed. They should be carried out at laboratories acceptable to the Administration.
The deviations in the values obtained by these tests, in respect of
those obtained during the type approval tests, should be within ranges acceptable to the
Tests under items 4.1, 4.3 and 4.4 should be carried out
on samples maintained at 60 °C or 24 hours and subsequently cooled to the test
According to paragraph 3.3 above.
According to paragraph 3.5 above.
4.3 Expansion ratio
According to paragraph 3.7
4.4 Drainage time
According to paragraph 3.8 above.
According to paragraph 3.10 above.
5 Interval of periodical controls
The first periodical control of foam concentrates stored on board
should be performed after a period of 3 years and, after that, every year.
A record of the age of the foam concentrates and of subsequent controls
should be kept on board.